Liquid crystal display device

ABSTRACT

The invention provides a liquid crystal display device for displaying an image, having a signal processing function and a narrow frame. In the display device of the invention, a signal processing circuit is formed by thin film elements and at least a portion of the signal processing circuit is formed in the region that extended the region where a wiring connection portion is formed along a side of a substrate. By providing the signal processing circuit outside the sealed region of liquid crystal and the like and utilizing regions beside an FPC connected portion which tended to be a dead space conventionally, a display device having a narrow frame can be provided.

BACKGROUND OF THE INVENTION

1. Field of the Invention The present invention relates to a displaydevice, and more particularly to a liquid crystal display device formedby a thin film semiconductor element.

2. Description of the Related Art

In recent years, portable phones are becoming more widely used inaccordance with the advancement of communication technology, and it isexpected that moving images or more amount of information will betransferred between them. Meanwhile, personal computers for mobile usethat are light in weight are produced, and information terminals such asa PDA originated in an electronic data book are manufactured and alsobecoming widespread in the society. As a result of the development ofdisplay devices, most of those portable information devices are providedwith flat panel displays such as a liquid crystal display device.

Among the active matrix liquid crystal display devices, a liquid crystaldisplay device having a thin film element such as a low-temperaturepolysilicon thin film transistor (the thin film transistor ishereinafter referred to as a TFT) is advanced toward commercializationin recent years. By using the low-temperature polysilicon TFTs, not onlypixels but a signal driver circuit can also be integrated in theperiphery of the pixels. Therefore, it is quite advantageous indownsizing and achieving high resolution of the display, thus thefurther spread thereof is expected.

On the other hand, portable information devices are required to beequipped with not only a visible display function but other outputfunctions such as an audio output function in particular. Displaying animage with audio makes the image more effective and amusing.

There are two types of audio signals for an audio output, which are ananalog audio signal and a digital audio signal. The analog audio signaldirectly obtains audio by a microphone or an audio device of analogoutput, while the digital audio signal obtains signals from digitalaudio devices such as a CD, an MD, and a DVD.

Moreover, an electronic device such as an IC recorder using asemiconductor memory such as a memory card other than the aforementionedCD, MD and the like are becoming to be widely used as a digital audiosignal source and expected to be spread further.

FIG. 6 is a block diagram showing a process of converting a digitalaudio signal into an analog audio signal. Most of the CD players and thelike have optical outputs, which inputs an optical signal to an opticalsensor 601 through fiber optics. The optical sensor 601 converts anoptical signal into an electronic signal. The electronic signal isdefined by CP-1201 standard of EIAJ and the like. Further, this signalis decoded into serial digital audio data by a demodulator 602 as shownin FIG. 9. There are three types of the decoded electronic signals asfor the CD, which are a base clock of 1.411 MHz, an LR clock of 44.1KHz, and digital audio signal data. The digital audio signal data istransferred to a serial-parallel converter circuit 603 in sequence froman MSB. The serial digital audio data is converted into parallel digitalaudio data by the serial-parallel converter circuit 603 and inputted toa D/A converter circuit 604 and converted into an analog audio signal.

FIG. 5 is an example of a conventional audio signal processing circuit.A D/A converter circuit to speaker driving terminals are shown in FIG.5. The audio signal processing circuit comprises a D/A converter circuit501, a D/A converter buffer circuit 502, a preamplifier 503, a speakerdriving non-inverted amplifier 504, a speaker driving inverted amplifier505, speaker driving terminals 506 and 507, coupling capacitors 508,509, and 510, filter capacitors 511 and 512, input resistors 514 and525, a preamplifier feedback resistor 516, a resistor 517, speaker driveamplifier gain setting resistors 518 to 520, a D/A converter circuitpower supply 521, a bias power supply 522, an analog-digital switch 523,and an analog signal input terminal 524.

Hereinafter described is an operation of the audio signal processingcircuit. The parallel digital audio signal is converted into an analogaudio signal by the D/A converter circuit 501 and inputted to the switch523 through the D/A converter buffer circuit 502 and the couplingcapacitor 508. On the other hand, an analog audio signal is inputtedfrom the input terminal 524 to the switch 523 through the couplingcapacitor 509. The switch 523 selects either the output signal from theD/A converter buffer circuit 502 or the analog input signal, and theselected signal is inputted to the preamplifier 503. The preamplifier503 amplifies the signal using the gain determined in response to theproportion of the preamplifier feedback resistor 516 and the resistor515. Subsequently, an output signal of the preamplifier 503 is amplifiedby the speaker driving non-inverted amplifier 504 and outputted to thespeaker driving terminal 506. Here, an example of a driving method ofBTL (Bridged Trans Less) in which opposite-phase signals are applied tothe both terminals of the speaker is described. An output of the speakerdriving terminal 506 is inverted by the speaker driving invertedamplifier 505 and outputted to the speaker driving terminal 507.

FIGS. 3A and 3B are a top plan view and a side view of a conventionaldisplay device. A pixel portion 308, a source signal driver circuit 305,and a gate signal driver circuit 306 are formed by TFTs on an insulatingsubstrate 301. Further, a sealing member 304 is sandwiched between theinsulating substrate 301 and the opposing substrate 302 for sealingliquid crystal and electronic signals are supplied to the liquid crystaldisplay device externally via an FPC (Flexible Printed Circuit) 303.Moreover, a TEG 312 for verifying characteristics and alignment marks310 and 311 for aligning the opposing substrate 302, a panel ID 309 andthe like are provided beside the connection portion with the FPC on thepanel.

Further, another example of a conventional display device which isdifferent from the aforementioned one is shown in FIGS. 2A and 2B. InFIG. 3A, TFTs surrounded with the sealing member 304 are only of thepixel portion 308, while a source signal driver circuit, a gate signaldriver circuit, and a signal processing circuit are surrounded with asealing member in FIG. 2A. A pixel portion 208, a source signal drivercircuit 205, a gate signal driver circuit 206, and a signal processingcircuit 207 are formed by TFTs on an insulating substrate 201. Further,a sealing member 204 is sandwiched between the insulating substrate 201and an opposing substrate 202 for sealing liquid crystal and electronicsignals are supplied to the liquid crystal display device externally viaan FPC 203. Moreover, a TEG 212 for verifying characteristics andalignment marks 210 and 211 for aligning the opposing substrate 202, apanel ID 209 and the like are provided beside the connection portionwith the FPC on the panel. A conventional technology can be referred inthe following document (For example, Patent Document 1)

[Patent Document 1]

Japanese Patent Laid-Open No. 2000-292805

SUMMARY OF THE INVENTION

In the conventional liquid crystal display device shown in FIGS. 3A and3B, a signal processing circuit has to be provided externally,therefore, the number of external elements are increased. In theconventional example shown in FIGS. 2A and 2B, the number of externalelements can be reduced, however, a signal processing circuit isincluded in the sealed region. Therefore, a periphery frame becomeslarge relatively to the display portion which makes the downsizing ofthe display device difficult.

In view of the aforementioned problems, it is one feature of theinvention that a liquid crystal display device in which at least aportion of a signal processing circuit is disposed in a region which isan extended region of a region where the connection portion is formed,which extended region extends along one side of the substrate.

In accordance with another feature of the invention, the liquid crystaldisplay device has, at least, a substrate, a pixel portion comprising aplurality of pixels, each of the plurality of pixels comprising a thinfilm element over the substrate, a wiring connection portion over afirst portion of the substrate, and a signal processing circuitcomprising a thin film element, at least a portion of the signalprocessing circuit being formed over a second portion of the substrate,wherein the first portion and the second portion are located beside asame edge of the substrate.

A liquid crystal display device has a pixel portion formed by aplurality of pixels by using thin film elements on a substrate. Theliquid crystal display device comprises a wiring connection portion onthe substrate and at least a portion of a signal processing circuitformed by thin film elements is disposed in a region which is anextended region of a region where the connection portion is formed,which extended region extends along one side of the substrate.

In accordance with one feature of the invention, the liquid crystaldisplay device having a pixel portion formed by a plurality of pixels byusing thin film elements on a substrate, the pixel portion is surroundedwith a sealing member, the liquid crystal display device comprises awiring connection portion on the substrate, at least a portion of asignal processing circuit formed by thin film elements is disposed in aregion which is an extended region of a region where the connectionportion is formed, which extended region extends along one side of thesubstrate, and the signal processing circuit is provided outside of thesealing member.

According to the aforementioned configurations, an area required for thesignal processing circuit can be reduced in the sealed region. Thus, anarea required for the frame can be reduced and the downsizing of aliquid crystal display device can be achieved.

In accordance with one feature of the invention, the liquid crystaldisplay device having a pixel portion formed by a plurality of pixels byusing thin film elements on a substrate, the liquid crystal displaydevice comprises a wiring connection portion on the substrate, and atleast a portion of an audio signal processing circuit formed by thinfilm elements is disposed in a region which is an extended region of aregion where the connection portion is formed, which extended regionextends along one side of the substrate.

In accordance with one feature of the invention, the liquid crystaldisplay device having a pixel portion formed by a plurality of pixels byusing thin film elements on a substrate, the pixel portion is surroundedwith a sealing member, the liquid crystal display device comprises awiring connection portion on the substrate, at least a portion of anaudio signal processing circuit formed by thin film elements is disposedin a region which is an extended region of a region where the connectionportion is formed, which extended region extends along one side of thesubstrate, and the audio signal processing circuit is provided outsideof the sealing member.

According to the aforementioned configurations of the invention, theaudio signal processing circuit may be an amplifier circuit.

According to the aforementioned configurations of the invention, theaudio signal processing circuit may be a decoder.

According to the aforementioned configurations of the invention, theaudio signal processing circuit may be a D/A converter circuit.

According to the aforementioned configurations, an area required for theaudio signal processing circuit can be reduced in the sealed region.Thus, an area required for the frame can be reduced and a downsizing ofa liquid crystal display device can be achieved.

In accordance with one feature of the invention, the liquid crystaldisplay device having a pixel portion formed by a plurality of pixels byusing thin film elements on a substrate, the liquid crystal displaydevice comprises a wiring connection portion on the substrate, at leasta portion of a signal processing circuit formed by thin film elements isdisposed in a region which is an extended region of a region where theconnection portion is formed, which extended region extends along oneside of the substrate, the signal processing circuit comprises an analogsignal processing circuit portion and a digital signal processingcircuit portion, and the digital signal processing circuit portion isprovided on the opposite side of the analog signal processing circuitportion with the wiring connection portion interposed therebetween.

In accordance with one feature of the invention, the liquid crystaldisplay device having a pixel portion formed by a plurality of pixels byusing thin film elements on a substrate, the liquid crystal displaydevice comprises a wiring connection portion on the substrate, at leasta portion of an audio signal processing circuit formed by thin filmelements is disposed in a region which is an extended region of a regionwhere the connection portion is formed, which extended region extendsalong one side of the substrate, and an input (terminal) of the signalprocessing circuit is provided on one side edge of the signal processingcircuit and an output (terminal) of the signal processing circuit isprovided on another side edge of the signal processing circuit.

In accordance with one feature of the invention, the liquid crystaldisplay device having a pixel portion formed by a plurality of pixels byusing thin film elements on a substrate, the liquid crystal displaydevice comprises a wiring connection portion on the substrate, at leasta portion of an audio signal processing circuit formed by thin filmelements is disposed in a region which is an extended region of a regionwhere the connection portion is formed, which extended region extendsalong one side of the substrate, wherein the signal processing circuitincludes a decoder, and an input (terminal) of the decoder is providedon one side edge of the signal processing circuit and an output(terminal) of the decoder is provided on another side edge of the signalprocessing circuit.

This is advantageous for avoiding an interference of signals between theinput and the output of the signal processing circuit.

In accordance with one feature of the invention, the liquid crystaldisplay device having a pixel portion formed by a plurality of pixels byusing thin film elements on a substrate, the pixel portion is surroundedwith a sealing member, the liquid crystal display device comprises awiring connection portion on the substrate, at least a portion of asignal processing circuit formed by thin film elements is disposed in aregion which is an extended region of a region where the connectionportion is formed, which extended region extends along one side of thesubstrate, the signal processing circuit is provided outside of thesealing member, the signal processing circuit comprises an analog signalprocessing circuit portion and a digital signal processing circuitportion, and the digital signal processing circuit is provided on theopposite side of the analog signal processing circuit portion with thewiring connection portion interposed therebetween.

In accordance with one feature of the invention, In the liquid crystaldisplay device having a pixel portion formed by a plurality of pixels byusing thin film elements on a substrate, the pixel portion is surroundedwith a sealing member, the liquid crystal display device comprises awiring connection portion on the substrate, at least a portion of asignal processing circuit formed by thin film elements is disposed in aregion which is an extended region of a region where the connectionportion is formed, which extended region extends along one side of thesubstrate, the signal processing circuit is provided outside of thesealing member, and an input (terminal) of the signal processing circuitis provided on one side edge of the signal processing circuit and anoutput (terminal) of the signal processing circuit is provided onanother side edge of the signal processing circuit.

In accordance with one feature of the invention, the liquid crystaldisplay device having a pixel portion formed by a plurality of pixels byusing thin film elements on a substrate, the pixel portion is surroundedwith a sealing member, the liquid crystal display device comprises awiring connection portion on the substrate, at least a portion of asignal processing circuit formed by thin film elements is disposed in aregion which is an extended region of a region where the connectionportion is formed, which extended region extends along one side of thesubstrate, wherein the signal processing circuit includes a decoder, thesignal processing circuit is provided outside of the sealing member, aninput (terminal) of the decoder is provided on one side edge of thesignal processing circuit and an output (terminal) of the decoder isprovided on another side edge of the signal processing circuit.

According to the aforementioned configurations, an area required for thesignal processing circuit can be reduced in the sealed region. Thus, anarea required for the frame can be reduced and the downsizing of aliquid crystal display device can be achieved. Further, a digital signalcan be prevented from leaking to an analog circuit, thus image and audiodata in higher quality can be provided.

In accordance with one feature of the invention, the liquid crystaldisplay device having a pixel portion formed by a plurality of pixels byusing thin film elements on a substrate, the liquid crystal displaydevice comprises a wiring connection portion on the substrate, at leasta portion of a signal processing circuit formed by thin film elements isdisposed in a region which is an extended region of a region where theconnection portion is formed, which extended region extends along oneside of the substrate, and at least a portion of the signal processingcircuit is covered with a resin.

In accordance with one feature of the invention, the liquid crystaldisplay device having a pixel portion formed by a plurality of pixels byusing thin film elements on a substrate, the liquid crystal displaydevice comprises a wiring connection portion on the substrate, at leasta portion of a signal processing circuit formed by thin film elements isdisposed in a region which is an extended region of a region where theconnection portion is formed, which extended region extends along oneside of the substrate, and at least a portion of the signal processingcircuit is covered with an adhesive protection.

In accordance with one feature of the invention, the liquid crystaldisplay device having a pixel portion formed by a plurality of pixels byusing thin film elements on a substrate, the pixel portion is surroundedwith a sealing member, the liquid crystal display device comprises awiring connection portion on the substrate, at least a portion of asignal processing circuit formed by thin film elements is disposed in aregion which is an extended region of a region where the connectionportion is formed, which extended region extends along one side of thesubstrate, the signal processing circuit is provided outside of thesealing member, and at least a portion of the signal processing circuitis covered with a resin.

In accordance with one feature of the invention, the liquid crystaldisplay device having a pixel portion formed by a plurality of pixels byusing thin film elements on a substrate, the pixel portion is surroundedwith a sealing member, the liquid crystal display device comprises awiring connection portion on the substrate, at least a portion of asignal processing circuit formed by thin film elements is disposed in aregion which is an extended region of a region where the connectionportion is formed, which extended region extends along one side of thesubstrate, the signal processing circuit is provided outside of thesealing member, and at least a portion of the signal processing circuitis covered with an adhesive protection.

According to the aforementioned configurations, an area required for thesignal processing circuit can be reduced in the sealed region. Thus, anarea required for the frame can be reduced and the downsizing of aliquid crystal display device can be achieved. Further, the signalprocessing circuit can be protected from external mechanical shock ormoisture, thus a reliability of the product is enhanced.

In accordance with one feature of the invention, the liquid crystaldisplay device having a pixel portion formed by a plurality of pixels byusing thin film elements on a substrate, the pixel portion is surroundedwith a sealing member, the liquid crystal display device comprises awiring connection portion on the substrate, at least a portion of anaudio signal processing circuit formed by thin film elements is disposedin a region which is an extended region of a region where the connectionportion is formed, which extended region extends along one side of thesubstrate, the audio signal processing circuit is provided outside ofthe sealing member, and the audio signal processing circuit comprises anamplifier circuit, and the amplifier circuit is provided adjacent to thewiring connection portion.

In accordance with one feature of the invention, the liquid crystaldisplay device having a pixel portion formed by a plurality of pixels byusing thin film elements on a substrate, the pixel portion is surroundedwith a sealing member, the liquid crystal display device comprises awiring connection portion on the substrate, at least a portion of anaudio signal processing circuit formed by thin film elements is disposedin a region which is an extended region of a region where the connectionportion is formed, which extended region extends along one side of thesubstrate, the audio signal processing circuit is provided outside ofthe sealing member, and the audio signal processing circuit comprises anamplifier circuit, and a wiring resistance between an output of theamplifier circuit and the wiring connection portion is 10Ω or less.

According to the aforementioned configurations, an area required for theaudio signal processing circuit can be reduced in the sealed region.Thus, an area required for the frame can be reduced and the downsizingof a liquid crystal display device can be achieved. Further, a fall inpotential due to the wiring resistance can be prevented, thus it is aquite advantageous configuration for a speaker drive amplifier and thelike which require a large current flow.

The invention provides a portable information device provided with theabovementioned liquid crystal display device.

In a conventional liquid crystal display device, a signal processingcircuit is provided externally or internally in the sealed region ofliquid crystal. Therefore, increase of external circuits and a framearea of a liquid crystal display are significant problems.

In the invention, by forming a signal processing circuit by thin filmelements on the substrate and disposing at least a portion of the signalprocessing circuit in the region which is an extended region of a regionwhere the connection portion is formed, which extended region extendsalong one side of the substrate, the signal processing circuit can beachieved without increasing external elements nor the frame area of aliquid crystal display device, thus a further downsizing of the liquidcrystal display device is realized.

BRIEF DESCRIPTION OF THE DRAWINGS

FIGS. 1A and 1B are a top plan view and a side view of the liquidcrystal display device of the invention respectively.

FIGS. 2A and 2B are a top plan view and a side view of the conventionalliquid crystal display device of the invention respectively.

FIGS. 3A and 3B are a top plan view and a side view of the conventionalliquid crystal display device of the invention respectively.

FIGS. 4A and 4B are a top plan view and a side view of the liquidcrystal display device of the invention respectively.

FIG. 5 is a block diagram of an audio signal processing circuit.

FIG. 6 is a block diagram of a digital audio signal processing circuit.

FIGS. 7A and 7B are a top plan view and a side view of the liquidcrystal display device of the invention respectively.

FIGS. 8A to 8G are diagrams of electronic devices each using the liquidcrystal display device of the invention.

FIG. 9 is a diagram showing a digital signal format of a CD.

FIG. 10 shows an embodiment of a block of a liquid crystal displaydevice integrated with an audio function.

FIG. 11 shows an embodiment of the electronic volume.

FIG. 12 is a picture of the liquid crystal display device using theinvention.

DETAILED DESCRIPTION THE INVENTION

Hereinafter described with reference to drawings are embodiment modes ofthe invention.

FIGS. 1A and 1B are a top plan view and a side view of the liquidcrystal display device of the invention respectively. In this embodimentmode, a display device is configured with a pixel portion 108 formed byTFTs on a insulating substrate 101, a source signal driver circuit 105,a gate signal driver circuit 106, a sealing member 104 for sealingliquid crystal, and an opposing substrate 102 as shown in FIGS. 1A and1B. An electronic signal for driving the liquid crystal display deviceis inputted via a wiring 103. Alignment marks 110 and 111, and a panelID 109 are provided beside the wiring connection portion. The inventionis different from the conventional configuration in that signalprocessing circuits 112 and 107 are provided in a region outside of thesealing member, which is an extended region of a region where theconnection portion is formed in the direction where the pixel portion isnot formed, that is beside the wiring connection portion in thisembodiment mode. As described above, by disposing a signal processingcircuit in a region which is an extended region of a region where theconnection portion is formed, which tended to be a dead spaceconventionally in the direction where the pixel portion is not formed,an area surrounded with the sealing member 104 can be reduced, thus theliquid crystal display device can be downsized.

It should be noted that the signal processing circuit described in thisspecification includes a variety of circuits such as an audio signalprocessing circuit, an image signal processing circuit, a controllercircuit, a CPU, and a memory circuit.

Embodiment 1

Hereinafter described is an embodiment in which an audio signalprocessing circuit is formed by thin film elements on an insulatingsubstrate according to the invention respectively. The audio signalprocessing circuit shown in FIG. 5A is considered now. FIGS. 7A and 7Bare a top plan view and a side view of the liquid crystal display deviceof the invention. As shown in FIGS. 7A and 7B, a display device isconfigured with a pixel portion 708 formed by TFTs on an insulatingsubstrate 701, a source signal driver circuit 705, a gate signal drivercircuit 706, a sealing member 704 for sealing liquid crystal, and anopposing substrate 702. An electronic signal for driving the displaydevice is inputted via an FPC 703 which is an example of the wiring, andalignment marks 710 and 711, and a panel ID 709 are provided beside aconnection portion with the FPC. As an audio signal processing circuitbeside the FPC connection portion, a digital signal circuit such as aD/A converter circuit 712, a D/A buffer circuit 713, or an amplifiercircuit such as a preamplifier 707, and speaker drive amplifiers 714 and715 are provided.

In an embodiment shown in FIGS. 7A and 7B, a digital signal system (aD/A converter circuit and a D/A buffer circuit) and an analog signalsystem (a preamplifier and a speaker driving amplifier) are provided onthe right and left of the connection portion with the FPC. According tothis alignment, a digital signal can be prevented from leaking to ananalog circuit, thus image and audio data in higher quality can beprovided A speaker driving amplifier is required to flow a large currentfor driving a speaker and is preferably disposed close to or adjacent tothe FPC connection portion in order to prevent the fall in potential dueto the wiring resistance. Further, it is preferable that a wiringresistance from an output terminal of an amplifier to the FPC be 10Ω orless. It is also preferable that a power supply wiring and a groundwiring have resistance of 10Ω or less. In addition, an image signal andan audio signal can be processed separately without interfering eachother, thus an image and audio in high quality can be provided.

The digital signal system is not limited to the D/A converter circuit,but may include other functions such as a DSP and a PCM decoder.

In order to prevent a digital input signal from influencing a signalafter D/A conversion, input and output terminals of a digital signalprocessing circuit such as a D/A converter circuit and a decoder may beprovided on the opposed side edges of the signal processing circuit.(not shown)

Embodiment 2

FIGS. 4A and 4B show an embodiment of the invention. FIGS. 4A and 4B area top plan view and a side view of the liquid crystal display device ofthe invention respectively. In this embodiment, a display device isconfigured with a pixel portion 408 formed by TFTs on an insulatingsubstrate 401, a source signal driver circuit 405, a gate signal drivercircuit 406, a sealing member 404 for sealing liquid crystal, and anopposing substrate 402 as shown in FIGS. 4A and 4B. An electronic signalfor driving the liquid crystal display device is inputted via an FPC403, and alignment marks 410, 411, and a panel ID 409 are provided closeto the FPC. Signal processing circuits 407 and 412 formed by TFTs areprovided right beside the FPC.

Besides the aforementioned elements, a resin 413 is provided in thisembodiment beside an FPC connection portion and the surface of thesignal processing circuit. The resin 413 is provided in order to protectthe signal processing circuits 407 and 412. By coating with a resin, thesignal processing circuit can be protected from external mechanicalshock or moisture, thus the reliability of the product is enhanced.

It should be noted the alignments marks 410 and 411 and a panel ID 409are not coated with a resin in this embodiment shown in FIGS. 4A and 4B.In this manner, a resin coating may be carried out selectively.

In terms of a mechanical protection, a protection is not limited to aresin, but an adhesive insulator such as a tape may be applied as aprotection or an insulating protection may be applied by using anadhesive. Further, a conductive protection may be applied by using aninsulating adhesive. These materials may be used in combination with aresin.

Embodiment 3

A liquid crystal display device formed in the aforementioned manner canbe applied to a display portion of a variety of electronic devices. Suchelectronic devices each having the liquid crystal display device formedaccording to the invention as a display medium are described below.

Such electronic devices include a video camera, a digital camera, a headmounted display (a goggle display), a game machine, a car navigationsystem, a personal computer, a portable information terminal (a mobilecomputer, a portable phone, an electronic book or the like) and thelike. Examples of those devices are shown in FIGS. 8A to 8G.

FIG. 8A illustrates a digital camera including a body 3101, a displayportion 3102, an image receiving portion 3103, operation keys 3104, anexternal connection port 3105, a shutter 3106 and the like. By using theliquid crystal display device of the invention in the display portion3102 of the digital camera, a small and light weight digital camera canbe provided.

FIG. 8B illustrates a notebook personal computer including a body 3201,a housing 3202, a display portion 3203, a keyboard 3204, an externalconnection port 3205, a pointing mouse 3206 and the like. By using theliquid crystal display device of the invention in the display portion3203, a small and light weight notebook personal computer can beprovided.

FIG. 8C illustrates a portable information terminal including a body3301, a display portion 3302, a switch 3303, operation keys 3304, aninfrared port 3305 and the like. By using the liquid crystal displaydevice of the invention in the display portion 3202, a small and lightweight portable information terminal can be provided.

FIG. 8D illustrates an image reproduction device (specifically, a DVDreproduction device) provided with a recording medium, including a body3401, a housing 3402, a recording medium (CD, LD, DVD or the like)reading portion 3405, an operation switch 3406, a display portion (a)3403, a display portion (b) 3404, and the like. The display portion (a)mainly displays image data while the display portion (b) mainly displaystext data. The liquid crystal display device of the invention can beapplied to the display portions (a) 3403 and (b) 3404 of the imagereproduction device provided with the recording medium. By using theinvention in a CD reproduction device, a game machine and the like, asmall and light weight image reproduction device can be provided.

FIG. 8E illustrates a folding portable liquid crystal display device. Byimplementing a display portion 3502 formed by using the invention into abody 3501, a small and light weight portable liquid crystal displaydevice can be provided.

FIG. 8F illustrates a video camera including a body 3601, a displayportion 3602, a housing 3603, an external connection port 3604, a remotecontrol receiving portion 3605, an image receiving portion 3606, abattery 3607, an audio input portion 3608, an eyepiece portion 3609,operations keys 3610 and the like. By using the liquid crystal displaydevice of the invention to the display portion 3602, a small and lightweight video camera can be provided.

FIG. 8G illustrates a portable phone including a body 3701, a housing3702, a display portion 3703, an audio input portion 3704, an antenna3705, an operation key 3706, an external connection port 3707 and thelike. By using the liquid crystal display device of the invention to thedisplay portion 3703, a small and light weight portable phone can beprovided.

As described above, application range of the invention is so wide thatit can be applied to electronic devices of various fields. Further, theelectronic devices described in this embodiment can be formed by anycombination of the configurations in Embodiments 1 and 2.

Embodiment 4

FIG. 10 shows a fourth embodiment of the invention. In this embodiment,a pixel portion 5001, a source signal driver circuit 5002, a gate signaldriver circuit 5003, a D/A converter circuit 5005, a serial-parallelconverter circuit 5004, a D/A buffer amplifier 5006, a level controlresistor 5007, a switch 5008, a preamplifier 5009, an electronic volume5010, an electronic volume buffer amplifier 5011, a speaker drivingnon-inverted amplifier 5012, and a speaker driving inverted amplifier5013 are formed in a liquid crystal display device by using thin filmtransistors.

Serial digital audio data is converted into parallel audio data by theserial-parallel converter circuit 5004. The serial-parallel convertercircuit 5004 is formed by a shift register and a latch circuit. Theparallel audio data is converted into an analog signal by the D/Aconverter circuit 5005 and inputted to the switch 5008 via the D/Abuffer amplifier 5006 and the level control resistor 5007. On the otherhand, an external analog audio signal is inputted to the switch 5008after being amplified by the preamplifier 5009. Here, the switch 5008selects either of the analog signal from the D/A converter circuit 5005or the analog signal amplified by the preamplifier 5009.

An output of the switch 5008 is inputted to the electronic volume 5010.An output signal of the D/A buffer amplifier 5006 of the D/A convertercircuit 5005 is divided in voltage between the level control resistor5007 and an input resistor of the electronic volume 5010, thus apotential is controlled between the D/A buffer amplifier 5006 and anoutput of the preamplifier 5009.

An output of the electronic volume 5010 is inputted to the speakerdriving non-inverted amplifier 5012 and the speaker driving invertedamplifier 5013. The output terminals of these amplifiers are connectedin a BTL configuration for driving the speaker 5014.

FIG. 12 is a picture of a prototype of the liquid crystal display deviceshown in FIG. 10. This is a 4-inch VGA liquid crystal display device.

FIG. 11 is an equivalent circuit of the electronic volume which isformed by a resistor, a switch, and a switch control circuit. An analogsignal is inputted from an analog signal input terminal and divided involtage by a resistor ladder. The divided signals are outputted to thevolume output terminal through a combination of switches. Each of theswitches is controlled by digital signals of D0 to D3. In the example ofFIG. 11, 4-bit signals are processed, however, the invention is notlimited to four bits. Further, a digital signal can be amplified byusing a level shifter and the like appropriately.

Although the present invention has been fully described by way ofEmbodiment Modes and Embodiments with reference to the accompanyingdrawings, it is to be understood that various changes and modificationswill be apparent to those skilled in the art. Therefore, unlessotherwise such changes and modifications depart from the scope of thepresent invention hereinafter defined, they should be constructed asbeing included therein.

1. A liquid crystal display device comprising: a substrate; a pixelportion comprising a plurality of pixels, each of the plurality ofpixels comprising a thin film element over the substrate; a wiringconnection portion over a first portion of the substrate; and a signalprocessing circuit comprising a thin film element, at least a portion ofthe signal processing circuit being formed over a second portion of thesubstrate; wherein the first portion and the second portion are locatedbeside a same edge of the substrate, and wherein an input (terminal) ofthe signal processing circuit is provided on one side edge of the signalprocessing circuit and an output (terminal) of the signal processingcircuit is provided on another side edge of the signal processingcircuit.
 2. A liquid crystal display device comprising: a substrate; apixel portion comprising a plurality of pixels, each of the plurality ofpixels comprising a thin film element over the substrate; a wiringconnection portion over a first portion of the substrate; and a signalprocessing circuit comprising a thin film element, at least a portion ofthe signal processing circuit being formed over a second portion of thesubstrate, wherein the signal processing circuit includes a decoder,wherein the first portion and the second portion are located beside asame edge of the substrate, and wherein an input (terminal) of thedecoder is provided on one side edge of the signal processing circuitand an output (terminal) of the decoder is provided on another side edgeof the signal processing circuit.
 3. A liquid crystal display devicecomprising: a substrate; a pixel portion comprising a plurality ofpixels, each of the plurality of pixels comprising a thin film elementover the substrate; a sealing member surrounding the pixel portion; awiring connection portion over a first portion of the substrate; and asignal processing circuit comprising a thin film element, at least aportion of the signal processing circuit being formed over a secondportion of the substrate, wherein the first portion and the secondportion are located beside a same edge of the substrate, wherein thesignal processing circuit is provided outside of the sealing member, andwherein an input (terminal) of the signal processing circuit is providedon one side edge of the signal processing circuit and an output(terminal) of the signal processing circuit is provided on another sideedge of the signal processing circuit.
 4. A liquid crystal displaydevice comprising: a substrate; a pixel portion comprising a pluralityof pixels, each of the plurality of pixels comprising a thin filmelement over the substrate; a sealing member surrounding the pixelportion; a wiring connection portion over a first portion of thesubstrate; and a signal processing circuit comprising a thin filmelement, at least a portion of the signal processing circuit beingformed over a second portion of the substrate, wherein the signalprocessing circuit includes a decoder, wherein the first portion and thesecond portion are located beside a same edge of the substrate, whereinthe signal processing circuit is provided outside of the sealing member,and wherein an input (terminal) of the decoder is provided on one sideedge of the signal processing circuit and an output (terminal) of thedecoder is provided on another side edge of the signal processingcircuit.
 5. A portable information device provided with the liquidcrystal display device according to claim
 1. 6. A portable informationdevice provided with the liquid crystal display device according toclaim
 2. 7. A portable information device provided with the liquidcrystal display device according to claim
 3. 8. A portable informationdevice provided with the liquid crystal display device according toclaim 4.